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(No Model.)

J. H. MADDEN.

GRINDING AND POLISHING WHEEL;

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UNITED STATES PATENT OFFICE.

JOHN H. MADDEN, OF NEW YORK, N. Y.

GRlNDING AND POLISHING WHEEL.

SPECIFICATION forming part of Letters Patent No. 287,144, dated October23, 1883.

Application filed September 1, 1883. (No model.)

To all whom it may concern.-

Be it known that I, J OHN H. MADDEN, of

New York, in the county of New York and State of New York, have inventedcertain Im; provementsin Grinding and Polishing Wheels, of which thefollowing is a specification. My invention relates to that class ofgrinding-wheels the operative surfaces of which are composed of emery,corundum, or other abrasive material molded into suitable form.

It is the aim of the invention to lessen the cost of manufacture, toreduce the weight so that the wheels may be driven with less power andat higher speeds, and to avoid the liability of fracture and the lossand danger attendant thereon.

To this end the invention consists in combining with a peripheral ringor rim acentral supporting hub or disk of paper, and in the peculiarmanner of shaping and uniting said parts.

Referring to the accompanying drawings, Figure 1 represents a centralcross-section of my improved wheel. Fig. 2 represents aside elevation ofthe same.

Referring to the drawings, A represents the rim or grinding-surface ofthe wheel, made in the form of a ring or hoop, with an inwardlyextending fiange, a, at one side.

B represents the hub or body, composed of paper, with its peripheryshaped to fit the interior of the rim and seated firmly therein, theflange of the rim being seated in and against the side face of the hub,as shown.

0 represents fastening-bolts, inserted transversely through the twoparts for the double purpose of preventing their lateral separation andholding the rim so that in the event of its being fractured its partswill not be thrown off by the centrifugal force developed. Inplace ofthe bolts other suitable connecting devices may be employed.

The rim may be molded of any of the various emery compounds known in theart, or of other suitable materials under pressure. 4 5

The hub or body is preferably constructed bysubj ecting superposedsheets of straw-board or paper to pressure, by a hydraulic press orotherwise, sufficient to unite them in a firm compact body. The hubismade of a diame- 5o ter slightly greater than the interior of the rim,and is forced to its place therein, this procedure insuring an intimatecontact between the parts and a firm support to the rim.

I am aware that grinding-wheels have been made with the removable rimsmounted upon metal-hubs and between metal clamps, and also that asoft-rubber ring has been introduced between a grinding-rim and acentral 6o hub, and I lay no claim thereto.

My paper body being light, moderately, elastic, a non-conductor of heat,and unaffected by changes in temperature or by the presence of moisturegives to my wheel a durability,'efficiency, and uniformity of wear notsecured by the use of any other material.

Having thus described my invention, what I claim is- 1. A grindingwheelconsisting of a ring of abrasive material and a central hub of paperseated firmly therein.

2. The flanged ring of abrasive material, combined with the rabbetedpaper hub and connecting devices, substantially as shown.

3. As a new article of manufacture, a grinding-wheel having a centralhub or body of compressed paper and a rim of abrasive material,substantially as described and shown.

JOHN H. MADDEN. Witnesses:

R BERT J. SMITH, J F. SHIELs.

